diff --git a/src/completer.ts b/src/completer.ts
index bcdaae25d..3139d476b 100644
--- a/src/completer.ts
+++ b/src/completer.ts
@@ -5,20 +5,22 @@ import * as vscode from 'vscode'
 import {Extension} from './main'
 import {Citation} from './providers/citation'
 import {Command} from './providers/command'
+import {Environment} from './providers/environment'
+import {Reference} from './providers/reference'
 
 export class Completer implements vscode.CompletionItemProvider {
     extension: Extension
     citation: Citation
     command: Command
-    reference: Citation
-    environment: Citation
+    environment: Environment
+    reference: Reference
 
     constructor(extension: Extension) {
         this.extension = extension
         this.citation = new Citation(extension)
         this.command = new Command(extension)
-        this.reference = new Citation(extension)
-        this.environment = new Citation(extension)
+        this.environment = new Environment(extension)
+        this.reference = new Reference(extension)
     }
 
     provideCompletionItems(document: vscode.TextDocument, position: vscode.Position, token: vscode.CancellationToken):
diff --git a/src/providers/environment.ts b/src/providers/environment.ts
new file mode 100644
index 000000000..2cd2acb1b
--- /dev/null
+++ b/src/providers/environment.ts
@@ -0,0 +1,146 @@
+'use strict'
+
+import * as vscode from 'vscode'
+import * as fs from 'fs'
+
+import {Extension} from './../main'
+
+export class Environment {
+    extension: Extension
+    suggestions: vscode.CompletionItem[]
+    provideRefreshTime: number
+
+    constructor(extension: Extension) {
+        this.extension = extension
+        this.suggestions = []
+        Object.keys(this.defaults).map(key => {
+            let item = this.defaults[key]
+            let environment = new vscode.CompletionItem(item.text,vscode.CompletionItemKind.Module)
+            this.suggestions.push(environment)
+        })
+    }
+
+    provide() : vscode.CompletionItem[] {
+        return this.suggestions
+    }
+
+    defaults = {
+        figure: {
+            text: 'figure'
+        },
+        table: {
+            text: 'table'
+        },
+        description: {
+            text: 'description'
+        },
+        enumerate: {
+            text: 'enumerate'
+        },
+        itemize: {
+            text: 'itemize'
+        },
+        math: {
+            text: 'math'
+        },
+        displaymath: {
+            text: 'displaymath'
+        },
+        split: {
+            text: 'split'
+        },
+        array: {
+            text: 'array'
+        },
+        eqnarray: {
+            text: 'eqnarray'
+        },
+        equation: {
+            text: 'equation'
+        },
+        equationAst: {
+            text: 'equation*'
+        },
+        subequations: {
+            text: 'subequations'
+        },
+        subequationsAst: {
+            text: 'subequations*'
+        },
+        multiline: {
+            text: 'multiline'
+        },
+        multilineAst: {
+            text: 'multiline*'
+        },
+        gather: {
+            text: 'gather'
+        },
+        gatherAst: {
+            text: 'gather*'
+        },
+        align: {
+            text: 'align'
+        },
+        alignAst: {
+            text: 'align*'
+        },
+        alignat: {
+            text: 'alignat'
+        },
+        alignatAst: {
+            text: 'alignat*'
+        },
+        flalign: {
+            text: 'flalign'
+        },
+        flalignAst: {
+            text: 'flalign*'
+        },
+        theorem: {
+            text: 'theorem'
+        },
+        cases: {
+            text: 'cases'
+        },
+        center: {
+            text: 'center'
+        },
+        flushleft: {
+            text: 'flushleft'
+        },
+        flushright: {
+            text: 'flushright'
+        },
+        minipage: {
+            text: 'minipage'
+        },
+        quotation: {
+            text: 'quotation'
+        },
+        quote: {
+            text: 'quote'
+        },
+        verbatim: {
+            text: 'verbatim'
+        },
+        verse: {
+            text: 'verse'
+        },
+        picture: {
+            text: 'picture'
+        },
+        tabbing: {
+            text: 'tabbing'
+        },
+        tabular: {
+            text: 'tabular'
+        },
+        thebibliography: {
+            text: 'thebibliography'
+        },
+        titlepage: {
+            text: 'titlepage'
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/providers/reference.ts b/src/providers/reference.ts
new file mode 100644
index 000000000..e5f4b8d1a
--- /dev/null
+++ b/src/providers/reference.ts
@@ -0,0 +1,66 @@
+'use strict'
+
+import * as vscode from 'vscode'
+import * as fs from 'fs'
+
+import {Extension} from './../main'
+
+export class Reference {
+    extension: Extension
+    suggestions: vscode.CompletionItem[]
+    provideRefreshTime: number
+
+    constructor(extension: Extension) {
+        this.extension = extension
+    }
+
+    provide() : vscode.CompletionItem[] {
+        if (Date.now() - this.provideRefreshTime < 1000)
+            return this.suggestions
+        this.provideRefreshTime = Date.now()
+        this.extension.manager.findAllDependentFiles()
+        let suggestions = {}
+        this.extension.manager.texFiles.map(filePath => {
+            let items = this.getReferencesTeX(filePath)
+            Object.keys(items).map(key => {
+                if (!(key in suggestions))
+                    suggestions[key] = items[key]
+            })
+        })
+        let items = this.getReferenceItems(vscode.window.activeTextEditor.document.getText())
+        Object.keys(items).map(key => {
+            if (!(key in suggestions))
+                suggestions[key] = items[key]
+        })
+        this.suggestions = []
+        Object.keys(suggestions).map(key => {
+            let item = suggestions[key]
+            let command = new vscode.CompletionItem(item.reference,vscode.CompletionItemKind.Reference)
+            this.suggestions.push(command)
+        })
+        return this.suggestions
+    }
+
+    getReferencesTeX(filePath: string) {
+        if (!(fs.existsSync(filePath)))
+            return {}
+        return this.getReferenceItems(fs.readFileSync(filePath, 'utf-8'))
+    }
+    
+    getReferenceItems(content: string) {
+        var itemReg = /(?:\\label(?:\[[^\[\]\{\}]*\])?){([^}]*)}/g
+        var items = {}
+        while (true) {
+            let result = itemReg.exec(content);
+            if (result == null) {
+                break
+            }
+            if (!(result[1] in items)) {
+                items[result[1]] = {
+                    reference: result[1]
+                }
+            }
+        }
+        return items
+    }
+}
\ No newline at end of file